Update on car,.
Knocking was failed bush on new wishbone, so have a had replacement sent.
Cleaned Maf ,map sensor and swirl valve. Very dirty but not cured smoke issue. However i imagine EGR will be heavily soiled too. Very difficult to access on 2.0 jtdm ,not sure how to take apart.
Whilst driving on motorway I lost complete turbo pressure and drove home with no turbo. Pressure returned and turbo boosting again but power down. Think lower intercooler hose has split even thou had recently repaired with silicone tape. Waiting for results on turbo, alfa dealer have sent it away for testing. ..:depressed